Wednesday, June 10, 2015

You're a process measurement and control engineer. Everybody is looking to you to make things work smoothly. When things fail, chances are someone is going to point a finger at you and ask why you didn't think of that bizarre confluence of events that managed to take things down. Let's look at a piece of your universe where some careful consideration will help keep disaster at bay.

Industrial Process Flow MetersCourtesy Siemens Industry, Inc.

Industrial processes require measurement to produce predictable, consistent, and desirable outcomes. It follows that there will be numerous data gathering points throughout the physical extent of the process, each staffed by a transmitter designed to measure temperature, pressure, flow, or some other process variable used to assure conformance of the operating process with its specifications. Each process measurement device must be carefully selected for accuracy, stability, and a number of other technical elements that make it well suited to measure the dynamic activity of your industrial process. Proper technical selection of the measurement hardware is certainly a key function that leads to a successful project. What other factors may play a role in delivering a well functioning, long lasting process measurement system?

The technical aspects of a process measurement and control device are but one consideration in product specification and installation. They come into play only when the device is working. Look at the event or condition possibilities, even those with very low perceived probability, that might take the measurement device out of action. Your research and good judgement, along with input from experienced application engineers will help you decide which to incorporate into your design and specifications.

Industrial Temperature Transmitters
Courtesy Siemens Industry, Inc.

Know the very extremes of weather conditions that may occur at the physical location of the device.Weather data for almost anywhere in the world, and certainly every major industrialized country, is readily available. Your device should be able to withstand the onslaught of any documented local condition on record, with some headroom included. Even if the process is planned to be shut down in unusual weather conditions, the temperature transmitter or other device you specified needs to be able to survive and immediately return to service when the process is restarted. Find local weather data and make it part of your process measurement device specification and selection process.

Know the process generated extremes that can impact device functionality.Of course, you will select a pressure transmitter or other measurement device to accommodate the generally expected conditions associated with the process. Consider, though, what other conditions might be produced coincidental to the process. There may be machinery, valves, or other physical events not contemplated here that might, on occasion, produce a local condition that can damage your transmitter. Look for potential sources of vibration, shock, temperature, or other elements that might have potential to take your measurement device out of service.

Know the security exposure of the device.Something rarely considered in the past, an assessment of who might want to commit malicious acts against the process stakeholders or the process itself, and how they might do it, should now be a part of all project designs at some level. Additionally, the ability for anyone to impact process operation, directly or indirectly, through its measuring devices should be well understood.

Know the physical contact hazards.Measurement devices need to be accessible for calibration, maintenance, even real-time observation in some cases. They also need to be protected from impact resulting from human activity related to operation, maintenance, and repair of nearby items. Often, flow meters or other process variable transmitters are located adjacent to traffic areas of the facility. This eases access for maintenance and repair, but also exposes the devices to damage from other activity along those traffic lanes. Consider the physical location and protection of installed devices to thwart the effects of unplanned contact with dollies, carts, boxes, dropped tools, and a host of other unpredictable happenings.

Know moisture.The vast array of modern industrial measurement devices employ electronics in their function. These electronics, along with possibly other parts of the device, must be protected from the harmful effects of moisture. Specify the proper enclosure and connection devices, as well as the manner in which they need to be installed in order to assure proper protection. The entrance of moisture into a device enclosure can be very slow, almost undetectable in the short term. Assure that barriers to moisture entry are adequate, as well as, in appropriate cases, a way for accumulated moisture to easily exit the enclosure.

Invest your time and effort to produce a solid installation with a trouble free life cycle. Then sleep well. Consult with an experienced engineering sales team for help with your application.